With this script, you will be able to retrieve the domain controller hostnames in a forest.

$myForest = [System.DirectoryServices.ActiveDirectory.Forest]::GetCurrentForest()
$myforest.Sites | % { $_.Servers } | Select Name, Domain

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References

MSDN Forest Class

Properties

	Name	Description
	ApplicationPartitions	Gets a collection of all application partitions in the forest.
	Domains	Gets a collection of all domains in the forest.
	ForestMode	Gets the operating mode of the forest.
	GlobalCatalogs	Gets a collection of all global catalogs in the forest.
	Name	Gets the name of the forest.
	NamingRoleOwner	Gets the domain controller that holds the FSMO naming master role for the forest.
	RootDomain	Gets the first domain that was created in a forest.
	Schema	Gets the schema of the forest.
	SchemaRoleOwner	Gets the domain controller that holds the FSMO schema master role for the forest.
	Sites	Gets a collection of sites that are contained in the forest.

Methods

	Name	Description
	CreateLocalSideOfTrustRelationship	Creates the local side of a trust relationship with the specified forest.
	CreateTrustRelationship	Creates both sides of a trust relationship with the specified forest.
	DeleteLocalSideOfTrustRelationship	Deletes the local side of a trust relationship.
	DeleteTrustRelationship	Deletes both sides of a trust relationship.
	Dispose()	Releases all managed and unmanaged resources that are held by the object.
	Dispose(Boolean)	Releases the managed resources that are used by the object and, optionally, releases unmanaged resources.
	Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	FindAllDiscoverableGlobalCatalogs()	Finds all of the discoverable global catalogs in this forest.
	FindAllDiscoverableGlobalCatalogs(String)	Finds all of the discoverable global catalogs in this forest in a specified site.
	FindAllGlobalCatalogs()	Finds all the global catalogs in this forest.
	FindAllGlobalCatalogs(String)	Finds all the global catalogs in this forest for a given site.
	FindGlobalCatalog()	Finds any global catalog in this forest.
	FindGlobalCatalog(LocatorOptions)	Finds a global catalog in this forest for a specified location criteria.
	FindGlobalCatalog(String)	Finds a global catalog in this forest for a specified site.
	FindGlobalCatalog(String, LocatorOptions)	Finds a global catalog in this forest for a specified site and location criteria.
	GetAllTrustRelationships	Gets a collection of the trust relationships of the current forest.
	GetCurrentForest	Gets a Forest object for the current user context.
	GetForest	Gets a Forest object for the specified context.
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetSelectiveAuthenticationStatus	Gets a Boolean value that indicates whether selective authentication is enabled on the inbound trust relationship with the specified forest. true if selective authentication is enabled; otherwise,false. For more information, see the Remarks section.
	GetSidFilteringStatus	Gets the SID filtering status of a trust.
	GetTrustRelationship	Gets the trust relationship between this forest and the specified forest.
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	RaiseForestFunctionality	Raises the mode of operation for the forest.
	RepairTrustRelationship	Repairs a trust relationship.
	SetSelectiveAuthenticationStatus	Enables or disables selective authentication for an inbound trust.
	SetSidFilteringStatus	Sets the SID filtering state with the specified forest.
	ToString	Returns a string representation of the current forest. (Overrides Object.ToString().)
	UpdateLocalSideOfTrustRelationship(String, String)	Updates the password for the local side of a trust relationship.
	UpdateLocalSideOfTrustRelationship(String, TrustDirection, String)	Updates the password and trust direction for the local side of a trust relationship.
	UpdateTrustRelationship	Updates the trust direction for a trust relationship. The trust directions are updated on both sides of the trust.
	VerifyOutboundTrustRelationship	Verifies that a previously established outbound trust with the specified forest is valid.
	VerifyTrustRelationship	Verifies that a previously established trust with the specified forest is valid.